Miniature dry cell battery

ABSTRACT

A dry cell battery construction suitable for providing multicell voltages in extremely small size is described. The construction uses a multi-cell container body to which are permanently fastened a cover member and a bottom member. Cell elements placed in each individual compartment are interconnected by connector means formed as a part of the cover and bottom members. The container body, cover and bottom together form the individual cell containers and no other cell containers are used in the assembly. Means for providing intermediate voltage taps may be included as a part of the construction.

United States Patent 1191 Spellman Apr. 2, 1974 [54] MINIATURE DRY CELLBATTERY 3,110,634 11/1963 Bradshaw 136 173 [76] Inventor: Patrick J.Spellman, Box 8109, P E A th Sk Middletown, Wis. 19101 aPaS PP 244,395 Adry cell battery construction suitable for providing multi-cell voltagesin extremely small size is described. [52] U S Cl 136/109 136/111136/173 The construction uses a multi-cell container body to [51] H0lm21/00 which are permanently fastened a cover member and [58] Fie'ld I111 173 a bottom member. Cell elements placed in each indi- 136/175 13213 5 R 1 Y vidual compartment are interconnected by connector meansformed as a part of the cover and bottom mem- [56] References Citedbers. The container body, cover and bottom together UNITED STATESPATENTS form the individual cell containers and no other cell containersare used in the assembly. Means for providing intermediate voltage tapsmay be included as a 1,823,066 9/1931 Shap1ro part of the construction.1,641,685 9/1927 Meisekothen... 3,078,329 2/1963 Granger l36/l08 8Claims, 3 Drawing Figures as so 42 X O K s 1 1 e I L l 4 5 Q 24 l O 26 l22 l I5 )7 19 21 l 1 12 (5 d d O Q 1 I I @QQ I 1 28 l J I J I I l 14 2a@3 25 I O 2? 1 E9 1 I 46 L X; 4/ 4 46 f l '5: I 6 34 L\ A\M v MINIATUREDRY CELL BATTERY BACKGROUND OF THE INVENTION 7 nected in series to givea battery voltage equal to the sum of the individual cell voltages. Theassemblage of cells is placed in a container often with potting compoundso as to present a convenient portable battery package. The manufactureof individual cells in metal containers has reached a high state ofperfection. Such cells have been miniturized in a construction known asa button cell so that a market product can now be found as small asabout 1 inch diameter and about l/lO inch high. Multi-cell batterieshave been built using such miniature cells. The assembly requires aboutthe same labor as is required to build a much larger battery, say offlashlight cells. Thus the assembly cost is completely out of linecompared to the battery size.

With the advent of the transistorized radio, a market for smallmulti-cell dry batteries developed. To meet this market, miniature cellsof the flat dry cell variety were developed. These cells are wrapped inpaper or paper like materials and are made as small as approximately Ainch X A inch l/lO inch thickness. The construction is suitable formechanical assembly, and these batteries, usually having six cells togive 9 volts, are now being made in quantity on fully automaticassemblylines.

The electronic watch of the type using a tuning fork opened a new marketfor small dry batteries. For technical reasons it was soon found that asingle cell battery of the button configuration provided the best powersource. To meet this market, buttoncells housed in steel cans areavailable. The usual size is about inch diameter by 1/10 inch inthickness. A new form of electronic watch has recently been developed.Its accuracy is reported to be within a few seconds per month. This typeof watch uses a completely electronic mechanism. The electricalrequirements call for a dual voltage battery. The low voltage portionrequires one or two cells with a comparatively high ampere hour capacityfor operation of the basic time measuring circuiting and a comparativelyhigh voltage source up to perhaps 10 cells of a much lower ampere hourcapacity to produce an illuminated time read-out. Some of the otherrequirements for the battery are that it have a long shelf life, that itmust develop the maximum power storage ability possible for its size andthat it does not leak dangerous chemicals even when subject tomechanical shock, temperature extremes, etc.

' The circuitry of this new watch is built upon the miniaturized chiptechnology. The entire electronic mechanism is not much larger than thebalance wheel of a normal mens wrist watch. Batteries built usingpresent day technologies have been found to be overly large and overlycostly to be in keeping with the rest of the watch. There is thus a needof a new technology for the production of extremely small high voltagebatteries of good electrical capacity and reasonable cost.

SUMMARY OF THE INVENTION A dry cell battery comprising a multi-cavitycontainer body with a cell element located in each cavity without othercell container means has permanently attachable container cover andcontainer bottom. The polarity of each element is positioned so thatadjacent cells locate their electrodes in an array alternately positiveand negative. Intercell connections as well as terminals form a part ofthe container top and bottom, so that as these parts are secured to thecontainer body the circuitry of the battery is completed. Intermediatetap-offs from the battery are provided. A bank of large cells (incomparison to the rest of the battery) can be provided to match theelectrical requirements of the time keeping mechanism. Hydrogen gasevolved from a certain class of cell anodes may be dissipated by thetransfusion of the gas through the container top and bottom members,thus preventing rupture and leakage of electrolyte from the battery.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts in an expanded view theparts used to make a 10 cell battery;

FIG. 2 depicts the assembled battery using parts as shown in FIG. 1; and

FIG. 3 depicts a second embodiment of the inven- IIOII.

DESCRIPTION OF THE PREFERRED EMBODIMENTS polyesters, ceramics, etc.Compartments 12 to 20 provide locations for 10 cell elements. Typicalcell elements are shown for cell 16 and 17. The elements comprise acathode 22, 23 an anode 24, 25 and a separator 26, 27. Electrolyte (notshown) is absorbed in pores in the cathode, anode and separator. Certainof the cathodes and anodes listed above are conveniently made bypressing dry powders into a pellet. In others, it may be convenient topress the powder into a small metal recepticle.

In a typical assembly and that used in the battery of FIG. 1, thecathode is somewhat larger than the anode. Compartments 28 are providedfor cathode and smaller compartments 30 are provided for the anode. Theseparator is made the same diameter as the cathode and is firmly pinchedbetween cathode and the container.

In order to obtain full battery voltage the cells are connected inseries. In the cell arrangement shown in FIG. 1, cell 12 connects tocell 13 and cell 13 to 14 and so on to cell 21. Each cell having anominal voltage of say 1.5, the battery voltage is 15 volts. Cells l2,14, 16, 18 and 20 are assembled with cathodes toward the top of theassembly as shown and anodes toward the bottom. Cells 13 to 21 areassembled with their cathodes toward the bottom and anodes toward thetop.

A cover member 32 and bottom member 34 complete the components of thebattery. The container, the cover member and the bottom member togetherform individual containers for the cells as well as forming the battery.Each cell element without other cell container means is located withinthe compartment included for it in the multicompartment container. Theabsence of individual cells with individual containers as described aspresent practice in the Background forms a principal feature of thepresent invention. Intercell connector means 36, 38 and terminals 40, 42and 44 are formed on the cover and bottom members as required. Theintercell connectors may be located on the cell side of the cover andbottom members or they may be located on the side of the members awayfrom the cells. In the construction shown they are located on the sidesaway from the cells. When this construction is used, it is necessary toprovide a current path through the cover and bottom members. Thisconnection may be provided by means such as a rivet, as insert molded inthe cover or bottom member or other means. It is necessary in thisconstruction that the connection be sealed in liquid tight relationshipto the cover or bottom member otherwise electrolyte may work through andpossibly reduce the capacity of the battery. On the cell side of thecover and bottom means the connector may end in a flat contact as at 46or it may extend into the cathode or anode, as shown at 48. Theintercell connector means such as 36, 38 may be individual pieces ofmetal fastened to the contact pieces. However, they may advantageouslybe made by printed circuit techniques as presently known in the art. Theintercell connectors may also be formed on the cell side of the coverand bottom members. In this case, it is important that the seal fromcell to cell is made in permanent liquid-tight fashion. Connector 38serves to connect the anode of cell 1 to the cathode of cell 2. Theconnector 36 serves to connect the anode of cell 2 to the cathode ofcell 3. The construction shown wherein the cathode of a first cellelement is adjacent the cover member, the anode of the first cellelement is adjacent the bottom member, the cathode of a second cellelement is adjacent the bottom member and the remaining elements beingin successive anode adjacent the bottom member and anode adjacent thecover member configuration, permits of a simple and direct intercellconnector layout. Terminals such as shown at 40 and 42 are located atthe voltage extremes of the battery. If it is required to provide anintermediate voltage, an intermediate terminal such as that shown at 44may be provided. The terminal form of 40 and 42 is a snap button. Thatat 44 is a pin. Other terminal shapes as known in the art may be used.

At 50, a variation of the intercell connection means is shown. In thiscase, it is in a zig-zag shape, increasing its length and increasing theleakage path from cell to cell.

When the several cell elements are properly located in the container 10,the cover member 32 and the bottom member 34 are placed thereon andfirmly and permanently fastened to the container as shown in FIG. 2.

In FIG. 3, 51 represents the container for a second embodiment of thebattery. In this case it is a 9 cell battery having a large cell 52 inthe center surrounded by 8 small cells 54, 56. As in the example ofFIGS. 1 and 2, cells are arranged in cathode up and down array. The

cell 52 provides a low voltage power source of high ca-' pacity foroperating the time keeping portion of a watch and cells 54, 56 provide ahigh voltage battery of low capacity for a read-out circuit.

Typical dimensions of a ten cell rectangular battery are: 0.9 inchlength, width 0.4 inch, height 0.19 inch, and of a battery like FIG. 3,diameter 1.0 inch, height A; inch.

As in all dry cell technology, it is important in this assembly to havethe cell elements under longitudinal (from anode to cathode) pressure soas to establish and maintain ionic and electronic contact between theseveral cell parts and to the intercell connector areas. In the presentdesign this is achieved by careful control of the thickness of thecontainer body, the thickness of the anode, cathode and separator and incertain cases by the use of a resilient separator such as syntheticfelt.

It is to be understood that the electrical requirements of aminiaturized chip technique electronic circuit are orders of magnitudesmaller than any usual electrical or electron mechanical circuit. Thepower requirements for the electronic watch differ materially fromearlier electical watches.

The seals between battery container and cover and bottom are made bynormal techniques suitable for their composition. For example withstyrene, a solvent seal is used, for polyolefins a heat seal, etc. It isimportant that all seals be liquid tight, particularly the seal betweenadjacent cells.

With a certain class of anodes, particularly those using zinc, a gasevolution problem exists. To minimize the gas evolution, it is customaryto treat the zinc metal with mercury or other chemicals. However, inspite of this a zinc negative may produce hydrogen gas. Most present daydry cells provide mechanical means for dissipating the hydrogen as it isformed. In the case of the miniature cells of the invention, it is notpossible to provide reliable individual mechanical vents in theavailable space. However, it is known that the classes of plasticslisted above when in thin section are permeable to hydrogen gas while atthe same time being relatively impermeable to water vapor. It is a partof the invention to make use of such plastics so as to further theminiaturization of the battery while still providing the reliability andfreedom from leakage demanded by the applications for which this batteryis intended.

Having thus fully described the battery of my invention and shown how itdiffers from other batteries known to the art, I hereby claim:

1. A multi-cell dry cell battery which comprises:

a. a plurality of cell elements, each cell element comprising an anode,a cathode, separation means and electrolyte;

b. a non conductive multi-compartment container having a top and abottom and including a compartment for each cell element;

c. a non conductive multi compartment cover permanently attached to thetop of the container;

d. a non conductive multi-compartment bottom member permanently attachedto the bottom of the container;

e. cell connecting means and terminal means formed integrally with thecover member and the bottom member;

f. the container, the cover member and the bottom member togetherforming individual containers for the cells; and,

g. each cell element without other cell container means being locatedwithin the compartment ineluded for it in the multi-compartmentcontainer.

2. A multi-cell dry cell battery as defined in claim 1 wherein the anodeof a first cell element is located adjacent the cover member, thecathode of the first cell element is located adjacent the bottom member,the anode of a second cell element is located adjacent the bottom memberand the cathode of the second cell element is located adjacent the covermember, the remaining cell elements being located in successive anodeadjacent cover member and anode adjacent the bottom memberconfiguration.

3. A multi-cell dry cell battery as defined in claim 2 wherein anegative terminal means connects to the anode of the first cell elementand a positive terminal means connects to the cathode of a last cellelement.

4. A multi-cell dry cell battery as defined in claim 3 wherein anintercell connector means located on the bottom member connects thecathode of the first cell element to the anode of the second cellelement, an intercell connector means located on the cover memberconnects the cathode of the second cell element to the anode of a thirdcell element and additional intercell connector means locatedsuccessively on the bottom member and the cover member serve to connectthe remaining cells elements serially into a multi-cell battery.

5. A multi-cell dry cell battery as defined in claim 4 wherein at leastthe first cell element of the battery is larger in ampere hour capacitythan other cell elements of the battery.

6. A multi-cell dry cell battery as defined in claim 5 wherein aterminal means connects to the intercell connector connecting a cellelement of larger ampere hour capacity to a cell element of small amperehour capacity.

7. A multi-cell dry cell battery as defined in claim 6 wherein the opencircuit voltage is no less than 6 volts, the diameter of the containerbody is no greater than 1.0 inch and the thickness of the container bodywith cover to bottom attached is no greater than Va inch.

8. A multi-cell dry cell battery as defined in claim 5 wherein thecontainer top member and the container bottom member is permeable tohydrogen gas and essentially impermeable to water vapor.

1. A multi-cell dry cell battery which comprises: a. a plurality of cellelements, each cell element comprising an anode, a cathode, separationmeans and electrolyte; b. a non conductive multi-compartment containerhaving a top and a bottom and including a compartment for each cellelement; c. a non conductive multi compartment cover permanentlyattached to the top of the container; d. a non conductivemulti-compartment bottom member permanently attached to the bottom ofthe container; e. cell connecting means and terminal means formedintegrally with the cover member and the bottom member; f. thecontainer, the cover member and the bottom member together formingindividual containers for the cells; and, g. each cell element withoutother cell container means being located within the compartment includedfor it in the multicompartment container.
 2. A multi-cell dry cellbattery as defined in claim 1 wherein the anode of a first cell elementis located adjacent the cover member, the cathode of the first cellelement is located adjacent the bottom member, the anode of a secondcell element is located adjacent the bottom member and the cathode ofthe second cell element is located adjacent the cover member, theremaining cell elements being located in successive anode adjacent covermember and anode adjacent the bottom member configuration.
 3. Amulti-cell dry cell battery as defined in claim 2 wherein a negativeterminal means connects to the anode of the first cell element and apositive terminal means connects to the cathode of a last cell element.4. A multi-cell dry cell battery as defined in claim 3 wherein anintercell connector means located on the bottom member connects thecathode of the first cell element to the anode of the second cellelement, an intercell connector means located on the cover memberconnects the cathode of the second cell element to the anode of a thirdcell element and additional intercell connector means locatedsuccessively on the bottom member and the cover member serve to connectthe remaining cells elements serially into a multi-cell battery.
 5. Amulti-cell dry cell battery as defined in claim 4 wherein at least thefirst cell element of the battery is larger in ampere hour capacity thanother cell elements of the battery.
 6. A multi-cell dry cell battery asdefined in claim 5 wherein a terminal means connects to the intercellconnector connecting a cell element of larger ampere hour capacity to acell element of small ampere hour capacity.
 7. A multi-cell dry cellbattery as defined in claim 6 wherein the open circuit voltage is noless than 6 volts, the diameter of the container body is no greater than1.0 inch and the thickness of the container body with cover to bottomattached is no greater than 1/8 inch.
 8. A multi-cell dry cell batteryas defined in claim 5 wherein the container top member and the containerbottom member is permeable to hydrogen gas and essentially impermeableto water vapor.